Cutting



Patented Dec. 3, 1946 CUTTING OIL Paul P. Gabriel, Bridgeport, Conn.

No Drawing. Application September 29, 1943, Serial No. 504,263

3 Claims.

The present invention relates to a composition of matter and particularly to a lubricant or cutting oil for use with cutting tools.

It has been found that when usual, known sulphur base oils were used in cutting operations,the resulting cuts were not consistently clean and burrs would be produced thereon. Also, the hole, during a tapping or drilling operation could not be readily held to the required tolerances after a relatively few operations. Further, tools thus lubricated were usually unable to stand the shock produced when the tool is rapidly moved into engagement with and along the work and many tools were broken. To avoid the breaking of tools, the speed of operation and speed of feed of the tool had to be held down and production reduced.

These difiiculties are overcome by the lubricant or cutting oil of the present invention which permits accurate cutting over long periods of use of the tool and produces a out having an extremely high finish with a minimum amount of burrs. Further, it enables the tool to be moved into engagement with and along the work at relatively high speeds without damage thereto and hence greatly reduces the breakage of tools and increases production of superior products.

The composition of the present invention comprises a commercial sulphur base oil, such as now used for cutting, and carbon tetrachloride. One such sulphur base oil is sometimes known as Union Base Oil, the trade-marked product of Sinclair Refining Company and is a mixture of about 88 parts of lard oil, 12 parts of sulphur and 2 parts of pine oil. The carbon tetrachloride employed is of the usual commercial quality. The preferred proportions of the mixture are 70% by volume of the sulphur base oil with 30% by volume of carbon tetrachloride. However, the proportions may be varied between 75% and 60% of sulphur base oil and 25% to 40% of carbon tetrachloride with satisfactory results.

In preparing th lubricating or cutting oil of the present invention, the sulphur base oil and carbon tetrachloride are mixed in the proportions noted above and are placed, preferably, in a closed container. The mixture is allowed to stand at room temperature of approximately 70 F, and age for a period of at least two weeks (or subjected to an equivalent aging action) or until the color of the mixture changes from a deep brown to a black with a greenish tint. This aging is essential to the production of a satisfactory cutting composition. I am not aware of the nature of the chemical reaction which takes place during this aging period, but I have determined that the 2 composition is ready for use when it has changed to a greenish black tint, and is not thoroughly satisfactory or efficient until this change takes place.

This cutting oil can be used in making exceptionally heavy cuts, such as on a lathe, milling or \planing machine, and equally well in making lighter cuts such as in drilling, tapping, threading or reaming.

A characteristic of the cutting oil of the present invention is that it permits the tools to more readily and precisely start the cutting operation and also enables them to withstand greater shocks. This results in greater precision in the cutting operation and permits an increase in the speed of operation of tne cutting tool and speed of feed of the tool into and along the work, tnus greatly decreasing tne tool breakage, increasing the life thereof, and speeding up production.

The lubricant of tne present invention is very effective when used during cutting operations on stainless steel or other hard alloys, and has been used with satisfactory results on softer metals, such as aluminum alloys and hard brass.

Another characteristic of the cutting oil is that, when used with all of these metals, there is a noticeable reduction of drag of the Work or chattering of the tool or work with the result that a highly finished cut surface with a minimum amount of burrs is produced and the cut is maintained accurate to gauge size.

It has also been found that the cutting oil of the present invention greatly retards the usual adherence of the metal of the workpiece to the cutting edge of the tool during the cutting operation. This is particularly true when sorter metals, such as aluminum alloys are being worked upon.

Because of the effectiveness of the composition of the present invention as a cutting lubricant and because of the fact that it readily adheres to the tool, relatively small amounts of the composition are required during use. This is of particular value in fine tapping, drilling and the like operations, inasmuch as the work can be readily seen without the view being obstructed by large quantities of the cutting oil and the precision operations carried out.

It will be seen, therefore, that I have, by the present invention, produced a cutting oil capable of permitting higher speeds of operation of the cutting tool with less damage to the tool and at the same time producing a superior cut surface on the work.

Variations and modifications may be made within the scope of this invention and portions of the improvements may be used without others.

I claim:

1. A lubricant or cutting oil composition comprising 25% to 40% by volume of carbon tetrachloride and 75% to 60% by volume of the reaction product of approximately 88 parts of lard oil, 12 parts of sulphur and 2 parts of pine oil, the composition being aged at approximately 70 F. for a period of about two weeks.

2. A lubricant or cutting oil composition comprising 30% by volume of carbon tetrachloride and 70% by volume of the reaction product of ap- .at room temperature of about 70 F. for a period of at least two weeks.

PAUL P. GABRIEL. 

